"Diggers in the Earth" by Eva March Tappan is an educational volume written in the early 20th century. As part of "The Industrial Readers" series, this book aims to provide children with engaging reading material while imparting knowledge about various industrial processes and the materials involved, including mining and the extraction of natural resources. It focuses on the importance and intricacies of how various natural materials, such as coal, granite, and metals, are sourced and utilized in everyday life. The opening of "Diggers in the Earth" introduces readers to the origins and formation of coal, detailing the ancient environments and biological processes that contributed to its creation. Tappan vividly describes the geological history that led to coal deposits, the methods of extraction from mines, and the evolution of mining techniques over centuries. Through engaging prose, she illustrates the daily life of coal miners, the various dangers they face while working, and the machinery that has transformed coal mining into a more efficient process. This engaging introduction sets the stage for a deeper exploration of industrial life in subsequent chapters, encompassing other materials and their significance in human society. (This is an automatically generated summary.)